Add.
Solution: There are many ways to solve this problem. Let's see two ways we can solve it. Place value table Let's line up the numbers by their decimal places. Ones $.$ Tenths ${3}$ $.$ ${0}$ $4$ $.$ ${5}$ Because $3$ is a whole number, we can add a decimal point and a $0$ behind to make the columns align. Now, let's add each place value column. Ones $.$ Tenths ${3}$ $.$ ${0}$ $+$ ${4}$ $.$ ${5}$ $\underline{~~~~}$ $\underline{~~~~}$ $\underline{~~~~}$ $7$ $.$ $5$ Decomposing the numbers We can group the whole numbers together and the decimals together. $\begin{aligned} &(3 + 4) + {0.5}\\\\ &=7 + {0.5}\\\\ &=7.5 \end{aligned}$ $7.5=3 + 4.5$